Damper for clothes driers



Oct. 2 1951: D. s. COLLINS 2,569,515

DAMPER FOR CLOTHES DRIERS Filed Aug. l0,' 1946 2 Sheets-Sheet l INVENTOR. C/[vz .s.

Oct. 2, 1951 D. s. COLLINS DAMPER FOR CLOTHES DRIERS Filed Aug. 10, 1946 Patented Oct. 2, 1951 DAMPER FOR CLOTHES DRIERS Donley S. Collins, Milwaukee, Wis., assignor to A. 0. Smith Corporation, Milwauk ee, Wis., a.

corporation of New York Application August 10, 1946, Serial No. 689,763

7 Claims. 1

This invention relates to a damper for clothes driers.

In drying clothes in a clothes drier by circulating hot air, in order to conserve on electricity or gas in the initial heating of the clothes and also to accomplish the drying operation in minimum time, it is desirable to accelerate the heating of the moist clothes to a temperature at which the moisture is driven off rapidly. It has been found that this may be accomplished by restricting the flow of hot air through the drum until certain temperatures are obtained such as 160 F. before permitting unrestricted flow of air through the drum. However, when the clothes are heated quickly a considerable amount of moisture is given off and the outlet pipe becomes full of water which results in injury to the pipe and the problem of having the water flow back into the unit rather than being discharged.

The principal object of the invention is to provide a damper unit that permits quick heating of the clothes and at the same eliminates collection of moisture in the outlet pipe.

Another object of the invention is to provide a damper in a clothes drier which is operated by the temperatures present in the unit.

A further object is to provide a damper in a clothes drier which permits air to flow through.

the outlet pipe without flowing through the drum of the drier.

Another object is to restrict the flow of air through the drier drum without restricting the flow of air through the discharge pipe or stack.

A further object is to dilute the air which comes from the drying chamber before it enters the blower to reduce the moisture content in the final exhaust from the drier.

Another object is to provide for drawing cool air into the spaces between the drying chamber and the outer panels to maintain both the panels and the controls of the drier substantially cool at all times.

These and other objects of the invention will appear hereinafter in'connection with the following description of several embodiments of the invention illustrated in the accompanying drawings.

In the drawings:

Figure 1 is a front elevation view of a clothes drier with parts broken away and sectioned;

Fig. 2 is a view of the drier from the right side with the side panel removed and with parts in elevation and section;

Fig. 3 is a top sectional view of Figure 1;

Fig. 4 is an enlarged fragmentary section of the damper assembly with the damper open; and

Fig. 5 is a view similar to Fig. 3 with the damper closed.

The clothes drier illustrated in the drawings as an example of a drier to which the invention may be applied, is similar to that described and claimed in the application of Adolph Pokras, entitled, Clothes Drier, Serial No. 626,788, filed November 5, 1945, now Patent No. 2,477,820, and granted August 2, 1949, assigned and to the assignee of the present invention.

The housing of the drier comprises the generally square casing I formed of front, rear and side panels assembled with a base 2 and closed at the top by the removable cover 3. A small door 4 in the front panel of the casing permits access to the inside.

The clothes carrying drum 5 is disposed for rotation within the casing and comprises a cylindrical perforated metal member which is closed at the ends by the front plate 6 and the rear plate 1.

A short horizontal shaft 8 has one end suitably secured to the center of rear plate I of the drum and the other end is mounted for rotation within bearing 9 suitably disposed within the rear end plate in which is secured to base 2 ,and supports drum 5 for rotation through short shaft 8.

The motor II is mounted on brackets l2 at the lower right hand rear corner of the drier. 'I'he motor i l by its shaft i3 drives drum 5 through a speed reducing unit and drive roll l4 preferably in a clockwise direction.

Motor shaft [3 extends through motor H and the front end of the shaft is directly connected to the rotor of the rotary blower unit l5 which is connected to the rear side of the wind box It or inlet conduit at the lower right hand front corner of the drier.

The outlet or exhaust pipe ll extends upwardly from blower unit l5 and then rearwardly and out through the rear of the drier to discharge the air circulated through the unit.

The drum 5 is surrounded by the inner baflle l8, and inner baflle I8 is partially surrounded on the left side, looking from the front in Figure l, by the outer bailie l9. Baiile I9 is radially spaced from baflle Hi to provide a chamber therebetween and is secured to the latter near the uppermost portion thereof. The baiiies are suitably secured to base 2 and extend the length of the unit from the rear end plate It to the front end plate 20. The front plate is secured to the base 2 and extends vertically between the drum and the front panel of the casing.

The drier is shown as supplied with heat by a gas burner unit 2| which is secured to base 2 between baffles l9 and I9 at the left side of the drier.

Air drawn into the unit by blower l5 enters through openings 22 in base 2 at the left side of the unit and throu h the openings 23 at the right side of the drier. The air entering through openings 23 passes over the top of the inner bailles l8 and I9 inside casing I and downwardly to enter the burner chamber through openings 23' in baffle l9, adjacent burner unit 2|. The air entering the burner chamber through openings 22 and 23 is heated by burner unit 2| in the gas chamber between baiiles l8 and 9 and then flows upwardly and enters the drum 5 through opening 24 in the upper portion of inner baille l8. The line of joinder of baffle l9 to batlle l8 previously described is at the uppermost side of opening 24 so that the air is forced to enter the drum through the opening 24.

If an electric heating unit is employed for heating the air the construction shownand described in the application previously referred to may be employed.

After circulating through drum 5, the air flows downwardly through the lint catcher 25 and into th lon itudinal passage 26 between the legs of baffle l8.

The air then flows from passage 26 through wind box l6 and is driven into the outlet pipe I'I by the blower l5.

Referring now more particularly to the invention the damper 21 is hinged to one side of wind box IE bv pivots 28 to open and close the opening 29 in the wind box.

Pivots 28 are located slightly removed from the top of opening 29 and the damper fits the opening so that the upper portion of the damper is free to swing inwardly when the damper opens.

The link or rod 30 is pivoted to the inside of damper 2'! at a central pivot 3| above pivots 28. The rod extends inwardly through wind box It and the inner end of the rod is joined to the expansible bellows thermostat 32. Thermostat 32 in turn is pivoted to bracket 33 which is suitably secured to base 2 within the longitudinal passage 26 between the legs of the battles.

Thermostat 32 is of the type that expands by heat and rod 30 is of such a length that when thermostat 32 is in a contracted position due to temperature conditions within the drier, damper '21 is open and air is drawn into the wind box IE through opening 29 and flows through blower unit l5 and out of outlet pipe IT. The thermostat may be set to expand at a temperature of 160 F. or other suitable temperature.

When the temperature within the drier reaches 160 F. or other suitable temperature for which the thermostat may be set, thermostat 32 expands and damper 21 closes opening 29 of the wind box through rod 30 by the lengthening of the thermostat.

When damper 21 is open air flows into the wind box without first flowing through drum 5. thereby allowing the air flowing through the heating chamber to attain a greater degree of heat and, as it passes through the'drum, to liberate this heat to the drum and the clothes therein.

The amount of heat absorbed by the air from the heating element or burner 2| and conveyed to the clothes is substantially increased, due to the retarded circulation through the heating chamber and drum, and theinitial heating of the clothes and drum is accomplished in a minimum of time and-with a minimum amount of heat.

In addition, due to the lower resistance to the flow of air to the blower unit IS, a higher velocity of air through blower unit l5 and outlet pipe I! is obtained, and as the moisture laden air from drum 5 is highly diluted by the drier air introduced through the damper opening 29, the tendency for the moisture to condense and collect in the blower unit l5 and outlet pipe H is prac tically eliminated.

Also, due to the higher velocity and drier air condition in outlet pipe II, the discharge from the outlet pipe, if made to the outdoor atmosphere in freezing weather, will have much less tendency to form frost at the exhaust end of the outlet pipe.

As the unit continues in operation the temperature in the drum due to the heating of the metal and clothes gradually builds up to the 160 F. or other temperature at which the thermostat is set. This results in expansion of the thermostat, and damper 21 then closes, and the air circulates through the drier and is discharged through outlet without any air flowing in through the damper.

The damper of the invention may be employed with any inlet conduit leading into the air stream which is flowing from drum 5 to blower unit IS. The conduit may be a wind box, as described. or the wind box may be eliminated and a pipe or conduit substituted which extends from the passage 26 to blower IS. The important requirement is that the damper be placed ahead of the blower unit in order that air may by-pass the drum and be sucked in through the damper opening and driven through the outlet pipe to maintain a continuous flow of air therethrough.

The damper 21 may also be pivoted so that the lower end pivots inwardly or outwardly to expose opening 29.

A further advantage of the invention lies in the cooling of the controls employed in the operation of the drier, and the outer casing. Controls, not shown, may be located in the housing 34 in the upper right front corner of the casing. Other controls for operation of the drier may be located between baflies l8 and IS on the base of the drier or may be located in other positions in the unit between the bailies and the outer casing.

It has been found that both the controls in housing 34, the panels of casing and motor II are cooled considerably when damper 21 is closed and air is flowing through the openings 23 on the right side of the drier viewed from the front in Figure 1 and over the outside of bafiles l8 and I9, through openings 23' into the burner chamher.

In operation the damper thermostat 32 is set so that air is flowing through the damper opening substantially at all times during the drying cycle. This provides the cooling effect on'the panels, controls and motor, described.

By providing for some flow of air through the damper opening for substantially the entire drying cycle air flowing from the drying drum for discharge is diluted before it enters the blower which reduces the moisture content of the air discharged from pipe ll.

By locating the damper in conjunction with a separate opening in the inlet conduit or wind box the flow of air through the conduit and outlet pipe is not restricted and moisture does not accumulate within the drier.

The invention provides for initial heating of the clothes in drum 5 in an accelerated rate of time and at the same time eliminates the problem of moisture collecting in the outlet pipe by providing for unrestricted flow 01' air through the blower and outlet pipe.

The invention also minimizes the tendency for frost to form at the exhaust end of outlet pipe II. when the pipe is exposed to freezing, due to the lower per cent of moisture in the discharged air and the higher velocity upon discharge.

Various embodiments 01' the invention may be em loyed within the scope of the accompanying claims.

I claim:

1. In a clothes drier, a rotary drier drum, a suction fan disposed to draw air therethrough to dry clothes confined therein. a heater for air passing into the drum, a doub e-walled casing for said drum having inlet ports for the entrance of air to the space between the walls of the easing and an opening from said space to said heater to suppl a part of the air to said heater and drum. a dam er disposed in the wall of said casin between said space and the entrance to the suction fan to by ass air which otherwise would pass throu h the heater and drum, and a thermostatic control for said damper responsive to the temperature of the air passing through the drum to control the bypass of air and maintain a predetermined temperature for the drying air in the drum.

2. In a clothes drier, a ro ary drier drum, a suction fan disposed to draw air therethrough to dry clothes confined therein, a heater for air passing into the drum. a double-walled casing for said drum having inlet ports for the entrance of a r to the space between the walls of the easing and an opening from said space to said heater to supply a part of the air to said heater and drum. a damper disposed in the wall of said casing between said space and the entrance to the suction fan to bypass air which otherwise would pass through the heater and drum. and a thermostatic control for said damper responsive to the temperature of the air passing through the said suction fan from the drier drum, and a thermostat disposed in said passage to be responsive to the temperature 01' the air passing to the suction ran from the drum and directly connected to said damper to move the same to an increased opening when the air temperature is low and toward Qosed position when the air temperature is high.

4. In a clothes drier, a rotary drier drum, a suction fan disposed to draw air therethrough to dry clothes confined therein, an outer casing for the drier, a baiiie surrounding the drum and having diametrically opposed passages therethrough for air entering and discharging from the drum, a heater disposed to heat the air entering through the inlet passage in said baflle, a chamber for said heater connected by an opening to receive air from the space between the casing and baiile at one side of the drier, a port opening to admit air to the casing at the side opposite said last named opening, a passage from the discharge opening in said baflie to the intake of the suction tan, and a damper disposed to admit air from the space between said cas ng and baille directly to said suction fan to thereby bypass air from said heater and drum during initial heating of the drum.

5. In a clothes drier, a rotary drier drum, a suction fan disposed to draw air therethrough to dry clothes confined therein, an outer casing for the drier. a baflle surrounding the drum and having diametrically opposed passages therethrough for air entering and discharging from the drum, a heater disposed to heat the air entering through the inlet passage in said bai'lle, a chamber for said heater connected by an opening to receive air from the space between the casing and baffle at one side of the drier, a port opening to admit air to the casing at the side opposite said last named opening. a passage from the discharge opening in said bafile to the intake of the suction fan, a damper disposed to admit air from the space between said casing and baiiie directly to said suction fan to thereby bypass air from said heater and drum during initial heating of the drum, and a thermostat disposed in said last named passage and connected to said damper to control the latter in response to the drum to control the bypass of air and maintain a predetermined temperature for the drying air in the drum, said thermostat control being set relative to the damper opening to provide for a substantially reduced flow of air through the heater and drum during initial drier operations and for a more rapid flow of heated air through the drum after the latter and the clothes therein have become heated, thereby providing a rapid initial heating of the drum and for maximum dilution of the discharged air at a time when it is most saturated with moisture.

3. In a clothes drier, a rotary drier drum, a suction fan disposed to draw air therethrough to dry clothes confined therein, a heater for air passing into the drum, a damper disposed below said drum to admit air to said suction fan from the outside, a passage disposed to admit air to varying temperature of air passing through the drum.

6. In a clothes drier, a rotary drier drum, a. suction fan disposed to draw air therethrough to dry clothes confined therein, an outer casing for the drier, a baflle surrounding the drum and having diametrically opposed passages therethrough for air entering and discharging from the drum, a heater disposed to heat the air entering through the inlet passage in said bafiie, a chamber for said heater connected by an opening to receive air from the space between the casing and battle at one side of the drier, a port opening to admit air to the casing at the side opposite said last named opening, a passage from the discharge opening in said bailie to the intake of the suction fan, a damper disposed to admit air from the space between said casing and battle directly to said suction fan to thereby bypass air from said heater and drum during initial heating of the drum, and a motor connected to drive said drum and said suction fan and disposed in the cold air stream between said casing and bafiie to be cooled thereby.

7. In a drier having a drying chamber with an inlet and outlet, a heater disposed to heat air REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Date Name Wiesebrock Mar. 21, 1882 Gelhaar July 15, 1919 Mahoney Apr. 29, 1924 Davis Oct. 16, 1928 Carroll Dec. 23, 1930 Schmidt Oct. 3, 1933 Peebles May 11, 1937 Strobridge Feb. 15, 1938 Lagodzinski Feb. 23, 1943 White Mar. 23, 1943 Moore Sept. 18, 1945 Hough Nov. 20, 1945 Broglie Apr. 23, 1946 

